Extra p53 Export Route

The tumor suppressor p53 is one of the best-characterized proteins, but it can still come up with a few surprises. Zhang and Xiong identified a second nuclear export signal (NES) in p53. This NES, which is close to the amino-terminus of the protein, is inactivated in response to phosphorylation, which is itself stimulated by DNA damage. The work elucidates one of the mechanisms by which cellular injury controls the distribution of this key protein in the body's cellular defenses against malignancy. See the Perspective by Gottifredi and Prives.